[PATCH V3 1/2] of: Add generic device tree DMA helpers

[Jassi Brar]

On 16 May 2012 22:42, Jon Hunter <jon-hunter at ti.com> wrote:

>>> What is still unclear to me, is if you use this token approach how
>>> readable is the device-tree? For example, if you have a client that can
>>> use one of two dmac and for each dmac the request/channel number is
>>> different, then by using a global token how can I determine what the
>>> options available for this client are?
>>>
>> Simple - you/client need not know about any option at all :)
>>
>> Client driver would simply request some channel and if it
>> doesn't get it, it bails out.
>>
>> It would be the DMACs' DT node that would contain that info.
>
> Yes, but what if I am doing some custom application and want to modify
> the mapping that is being used? So I just wanted to make sure it is easy
> to understand assuming that you understand what your h/w is capable of.
>
Any scenario when a client would want to choose which dma controller
it runs on?

Because when we say a client could be provided a channel on any of the
two given dmacs, it implies that the client wouldn't feel any difference.